检索结果-内蒙古大学图书馆

Phenomenological 3D and 1D consistent models for shape-memory alloy materials

COMPUTATIONAL MECHANICS 2009年第3期44卷 405-421页

作者： Evangelista, Veronica Marfia, Sonia Sacco, Elio Univ Cassino Dipartimento Meccan Strutture A&T I-03043 Cassino Italy

The paper deals with the modeling and the development of a numerical procedure for the analysis of shape-memory alloy (SMA) elements in order to predict the main features of SMA devices. A 3D SMA model in the framework of small strain theory is developed starting from the thermo-mechanical model proposed by Souza et al. (Eur J Mech A/Solids 17:789-806, 1998) and modified by Auricchio and Petrini (Int J Numer Methods Eng 55:1255-1284, 2002). The aim of this paper is to propose some more modifications to the original model, to derive its consistent 1D formulation, to clarify the mechanical meaning of the material parameters governing the constitutive model. A robust time integration algorithm is developed in the framework of the finite element method and a new beam finite element is proposed. Some numerical applications and a comparison with experimental data available in literature are carried out in order to assess the ability of the proposed model to describe the SMA behavior.

关键词： Shape-memory alloys Solid phase transformations Thermodynamically-based formulations 3D and 1D consistent constitutive models numerical algorithm Return mapping

来源：评论

学校读者我要写书评

暂无评论

Analysis of post-buckling branches at multiple symmetric bifurcations

引用

INTERNATIONAL JOURNAL FOR numerical METHODS IN ENGINEERING 2001年第4期51卷 413-428页

作者： Magnusson, A Univ Lund Div Solid Mech S-22100 Lund Sweden

A method to analyse and solve symmetric bifurcations by establishing the bifurcation equations using an asymptotic expansion method is presented. The bifurcation equations are obtained using a decomposition of the spaces by means of the theory of Lyapunov-Schmidt, To solve the bifurcation equations an asymptotic expansion method along the lines of Koiter is applied. The expansion is presented in a form suited for implementation in a finite element context. The present paper is focused on the treatment of symmetric multiple bifurcations where new forms of the bifurcation equations are established. The accuracy of the method is verified with three examples. Copyright (C) 2001 John Wiley & Sons, Ltd.

关键词： numerical algorithm symmetric bifurcation asymptotic expansion FEM

来源：评论

学校读者我要写书评

暂无评论

Gradient-Based Parameter Identification algorithms for Observer Canonical State Space Systems Using State Estimates

引用

CIRCUITS SYSTEMS AND SIGNAL PROCESSING 2015年第5期34卷 1697-1709页

作者： Ma, Xingyun Ding, Feng Jiangnan Univ Key Lab Adv Proc Control Light Ind Minist Educ Wuxi 214122 Peoples R China Jiangnan Univ Control Sci & Engn Res Ctr Wuxi 214122 Peoples R China

This paper considers the parameter identification problem of the state space observer canonical model for linear stochastic systems, and proposes a Kalman filter-based gradient iterative algorithm and an observer-based multi-innovation stochastic gradient algorithm. The fundamental idea is to replace the unmeasurable states in the information vector with the estimated states and to compute the states of the systems through the Kalman filter or the state observer using the previous parameter estimates. Examples are provided to confirm the effectiveness of the proposed algorithms.

关键词： numerical algorithm Stochastic gradient Identification Multi-innovation identification theory Kalman filter State space model

来源：评论

学校读者我要写书评

暂无评论

The constrained interpolation profile method for multiphase analysis

引用

JOURNAL OF COMPUTATIONAL PHYSICS 2001年第2期169卷 556-593页

作者： Yabe, T Xiao, F Utsumi, T Tokyo Inst Technol Dept Mech Engn & Sci Meguro Ku Tokyo 1528552 Japan Japan Atom Energy Res Inst Kansai Res Estab Adv Photon Res Ctr Neyagawa Osaka 5720019 Japan SEAVANS N Frontier Res Syst Global Change Minato Ku Tokyo 1056791 Japan

We present a review of the constrained interpolation profile (CIP) method that is known as a general numerical solver for solid, liquid, gas, and plasmas. This method is a kind of semi-Lagrangian scheme and has been extended to treat incompressible flow in the framework of compressible fluid. Since it uses primitive Euler representation, it is suitable for multiphase analysis. The recent version of this method guarantees the exact mass conservation even in the framework of a semi-Lagrangian scheme. We provide a comprehensive review of the strategy of the CIP method, which has a compact support and subcell resolution, including a front-capturing algorithm with functional transformation, a pressure-based algorithm, and other miscellaneous physics such as the elastic-plastic effect an;l surface tension. Some practical applications are also reviewed, such as milk crown or coronet, laser-induced melting, and turbulent mixing layer of liquid-gas interface. (C) 2001 Academic Press.

关键词： numerical algorithm semi-Lagrangian schemes interface capturing fluid dynamics mass conservation multiphase flows surface tension rheological materials

来源：评论

学校读者我要写书评

暂无评论

Heat transfer analysis of intermittent grinding processes

引用

INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER 2008年第15-16期51卷 4132-4138页

作者： Perez, J. Hoyas, S. Skuratov, D. L. Ratis, Yu. L. Selezneva, I. A. de Cordoba, P. Fernandez Urchueguia, J. F. Univ Politecn Valencia Dept Appl Math Valencia Spain Tech Univ Madrid Dept Thermodynam Madrid Spain Samara State Aerosp Univ Dept Engines Samara Russia Samara State Aerosp Univ Dept Informat Samara Russia Univ Politecn Valencia Dept Appl Phys Valencia Spain

An analytical solution for a two-dimensional boundary-value problem that models the transfer of heat to the workpiece during an intermittent grinding process has been previously constructed. In this solution, two variable functions in the boundary condition of the problem described the interrelation between the grinding wheel, the workpiece and the grinding fluid. In this paper, a numerical algorithm is developed. This algorithm allows one to study the effect on the workpiece temperature of varying either the velocity of the workpiece and/or the cycle-times related parameters. Our objective is to determine the values of the appropriate parameters so that the amount of material removed is maximized and the amount of coolant required is minimized. (C) 2008 Elsevier Ltd. All rights reserved.

关键词： grinding process boundary-value problem analytical solution numerical algorithm

来源：评论

学校读者我要写书评

暂无评论

Optimized sparse fractional Fourier transform: Principle and performance analysis

引用

SIGNAL PROCESSING 2020年 174卷 107646-107646页

作者： Zhang, Hongchi Shan, Tao Liu, Shengheng Tao, Ran Beijing Inst Technol Sch Informat & Elect Beijing 100081 Peoples R China Southeast Univ Sch Informat Sci & Engn Nanjing 210096 Peoples R China

For the input signals that can be sparsely represented in the fractional Fourier domain, sparse discrete fractional Fourier transform (SDFrFT) has been proposed to accelerate the numerical computation of discrete fractional Fourier transform. While significantly alleviating the computational load, SDFrFT has narrow applicability since it is more suitable for large-scale input signals. In this regard, the objective of this work is to overcome the limitation and further optimize the numerical computation of SDFrFT by exploiting the underlying phase information. We first employ Neyman-Pearson approach to achieve a noise-robust detection. Then, we derive the probability distribution function of the phase error in the location stage and, accordingly, design a location error correction algorithm. The proposed algorithm, termed optimized sparse fractional Fourier transform (OSFrFT), can reduce the computational complexity while guarantee sufficient robustness and estimation accuracy. Simulation results are provided to validate the effectiveness of the proposed algorithm. A successful application of OSFrFT to continuous wave radar signal processing is also presented. (C) 2020 Elsevier B.V. All rights reserved.

关键词： Fractional Fourier transform Time-frequency analysis Computational complexity Sparse representation numerical algorithm

来源：评论

学校读者我要写书评

暂无评论

The effects of different parameters of pyramidal textured silicon surface on the optical reflectance

引用

SOLAR ENERGY 2016年 134卷 392-398页

作者： Yang, Shengyao Ge, Peiqi Zhang, Lei Shandong Univ Sch Mech Engn Jinan 250061 Peoples R China Shandong Univ Minist Educ Key Lab High Efficiency & Clean Mech Manufacture Jinan 250061 Peoples R China

The effects of different light trapping structure, as formed on the surface of silicon solar cells to increase the light trapping efficiency, are different on the optical reflectance and absorptance. The aim of this paper is to study the effects of the incident angle and pyramidal textured surface formed mechanically on the light trapping efficiency. The base angle size can be controlled mechanically to break through the limitation of crystal structure, and a fillet on the included angle between neighboring pyramidal structures was obtained unavoidable. A numerical algorithm was developed to calculate the weighted reflectance of different structure in this work. Every light transmission process was tracked and the weighted reflectance was calculated numerically. Then the light trapping efficiency of the pyramid texture with different parameters was obtained and analyzed. The weighted reflectance in changed conditions was calculated respectively. By analyzing the values, the optimized parameters of the pyramid texture were proposed, and the best incident angle was obtained. (C) 2016 Elsevier Ltd. All rights reserved.

关键词： Silicon solar cells Light trapping structure numerical algorithm Weighted reflectance

来源：评论

学校读者我要写书评

暂无评论

A comparison of DHW algorithm for temperature distribution calculation with Fourier's algorithm for transmission of heat between discrete bodies

引用

INTERNATIONAL JOURNAL OF THERMOPHYSICS 2007年第3期28卷 891-905页

作者： Gembarovic, Jozef Gembarovic, Jozef, Jr. TPRL Inc W Lafayette IN 47906 USA Purdue Univ Coll Technol W Lafayette IN 47906 USA

In this article, our damped-heat wave (DHW) algorithm for the calculation of temperature distribution in a homogeneous finite medium is compared with Fourier's algorithm for transmission of heat between discrete b... 详细信息

关键词： heat conduction numerical algorithm temperature distribution

来源：评论

学校读者我要写书评

暂无评论

Fluid flow in an enclosed cavity of rotational bioreactor for bone tissue engineering

引用

THERMOPHYSICS AND AEROMECHANICS 2019年第6期26卷 901-909页

作者： Larionov, P. M. Ganimedov, V. L. Maslov, N. A. Tsibulskaya, E. O. Novosibirsk State Univ Novosibirsk Russia RAS SB Khristianovich Inst Theoret & Appl Mech Novosibirsk Russia

The developed mathematical model was applied for study of fluid dynamics in a rotational bioreactor for bone tissue engineering by in vitro technology. The research goal is finding an optimal mode for rotation ensuring proper cyclic loading from fluid upon the cell-seeded biomaterial. The basis for developing a mathematical model of a bioreactor was a design of rotational type biological reactor used in medical research;the liquid flow is generated through viscosity mechanism due to surface rotation. Mathematical description of flow in a reactor cavity was performed with Navier-Stokes equations. It was assumed that flow regime in the boundary layer is laminar. numerical algorithm was accomplished using a fluid flow solver "Fluent" in the code package ANSYS-12. Four variants of generating the rotational motion in the reactor cavity were considered. A series of parametric computations was performed for the rotation frequency f in the range 0.05 <= f <= 0.25 Hz. The paper offers visualization of velocity fields in the vertical plane. The distributions for shear stress and pressure in the working zone of reactor were calculated and analyzed. Simulations demonstrated that a method of fluid rotation by driving the outer cylinder with an offset axis is the best for arranging a cyclic pressure and cyclic shear stress on the biological material.

关键词： mathematical simulation numerical algorithm rotational bioreactor Taylor's vortices Navier-Stokes equations laminar flow shear stress coaxial cylinders scaffold

来源：评论

学校读者我要写书评

暂无评论

Extreme low and high water levels

引用

COASTAL ENGINEERING 2005年第1期52卷 63-77页

作者： Sobey, RJ Univ London Imperial Coll Sci Technol & Med Dept Civil & Environm Engn London SW7 2AZ England

A methodology for the prediction of low end and high end extremes in sustained water level is established. The observational data base is a long-duration sequence of monthly high and low extremes. The data identifies a deterministic trend attributable to Mean Sea Level rise and the nominal 19-year forcing in the astronomical tide. The data is pre-conditioned to remove these trends, defining a net data series suitable for extreme value analysis. Context-specific issues in the extreme value analysis are identified and resolved. These include probability model compatibility with elevation datums, rational estimation of the distribution parameters, and the estimation of confidence limits. The predictions for extreme low and high water levels are both real time and return period dependent. (C) 2004 Elsevier B.V. All rights reserved.

关键词： extreme value analysis high water level low water level numerical algorithm sea level rise 19-year cycle

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：